The association between sex and neonatal respiratory distress syndrome

BACKGROUND

To investigate the association between sex and neonatal respiratory distress syndrome (NRDS).

METHODS

Neonates born at our hospital and transferred to the neonatal department within 1 h were retrospectively analyzed. Depending on whether they developed NRDS during their hospital stay, the neonates was divided into NRDS and non-NRDS groups. There were 142 neonates in the NRDS group (95 males and 47 females) and 310 neonates in the non-NRDS group (180 males and 140 females). The neonates' data on gestational age (GA), sex, birth weight, white blood cell count (WBC), platelet count (PLT), C-reactive protein (CRP), total immunoglobulin M (total IgM), gestational diabetes mellitus(GDM), antenatal steroids use, meconium-stained amniotic fluid, and preterm premature rupture of membranes(PPROM) were gathered.

RESULTS

452 neonates (265 males and 187 females) were involved for the purpose of collecting basic characteristic. Multivariate analysis, males had a 1.87 times higher risk of NRDS than females (P < 0.05) after controlling for the confounding effects of GA, birth weight, WBC, PLT, CRP, total IgM, GDM, antenatal steroids use, meconium-stained amniotic fluid, and PPROM.

CONCLUSIONS

Sex was associated with NRDS; males had a considerably higher risk of NRDS than females.

Factors influencing C-reactive protein status on admission in neonates after birth

OBJECTIVE

To explore the factors influencing C-reactive protein (CRP) status in neonates on admission after birth.

METHODS

820 newborns born and hospitalized at Xiangya Hospital of Central South University from Jan. 2020 to Dec. 2020 were retrospectively analyzed. Maternal medical history and medication use during pregnancy, neonatal demographic information and status at birth were collected through the electronic medical record system. Statistical software was used to analyze the possible relationship between perinatal factors and CRP on admission after birth.

RESULTS

A total of 820 neonates were analyzed, including 463 males and 357 females with a mean gestational age (GA) of 36.07 ± 3.30 weeks. (1) Multifactor Logistic regression analysis: larger GA (OR: 1.13, 95%CI: 1.00-1.28, P = 0.042), premature rupture of membranes (PROM) ≥ 18 h (OR: 2.39, 95%CI: 1.35-4.23, P = 0.003) and maternal autoimmune diseases (OR: 5.30, 95%CI: 2.15-13.07, P < 0.001) were independent risk factors for CRP ≥ 8 mg/L. Cesarean delivery (OR 0.40, 95%CI: 0.26-0.60, P < 0.001) was independent protective factor for CRP ≥ 8 mg/L. (2) Threshold effect analysis: A non-linear relationship was found between GA and CRP. When GA is less than 33.9 weeks, the risk of CRP ≥ 8 mg/L was reduced by 28% with one week increased (P < 0.001), and when GA is more than 33.9 weeks, the risk of CRP ≥ 8 mg/L was increased by 61% with one week increased (P < 0.001).

CONCLUSIONS

GA, PROM, maternal autoimmune diseases and cesarean delivery were all independent influences neonatal CRP ≥ 8 mg/L on admission, and there was a nonlinear relationship between GA and neonatal CRP ≥ 8 mg/L on admission.

Omentin-1 induces mechanically activated fibroblasts lipogenic differentiation through pkm2/yap/pparγ pathway to promote lung fibrosis resolution

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by extensive extracellular matrix (ECM) deposition by activated myofibroblasts, which are specialized hyper-contractile cells that promote ECM remodeling and matrix stiffening. New insights on therapeutic strategies aimed at reversing fibrosis by targeting myofibroblast fate are showing promise in promoting fibrosis resolution. Previously, we showed that a novel adipocytokine, omentin-1, attenuated bleomycin (BLM)-induced lung fibrosis by reducing the number of myofibroblasts. Apoptosis, deactivation, and reprogramming of myofibroblasts are important processes in the resolution of fibrosis. Here we report that omentin-1 reverses established lung fibrosis by promoting mechanically activated myofibroblasts dedifferentiation into lipofibroblasts. Omentin-1 promotes myofibroblasts lipogenic differentiation by inhibiting dimerization and nuclear translocation of glycolytic enzymes pyruvate kinase isoform M2 (PKM2) and activation of the downstream Yes-associated protein (YAP) by increasing the cofactor fructose-1,6-bisphosphate (F1, 6BP, FBP). Moreover, omentin-1 activates proliferator-activated receptor gamma (PPARγ) signaling, the master regulator of lipogenesis, and promotes the upregulation of the lipogenic differentiation-related protein perilipin 2 (PLIN2) by suppressing the PKM2-YAP pathway. Ultimately, omentin-1 facilitates myofibroblasts transformation into the lipofibroblast phenotype, with reduced collagen synthesis and enhanced degradation properties, which are crucial mechanisms to clear the ECM deposition in fibrotic tissue, leading to fibrosis resolution. Our results indicate that omentin-1 targets mechanical signal accelerates fibrosis resolution and reverses established lung fibrosis by promoting myofibroblasts lipogenic differentiation, which is closely associated with ECM clearance in fibrotic tissue. These findings suggest that targeting mechanical force to promote myofibroblast lipogenic differentiation is a promising therapeutic strategy against persistent lung fibrosis.

A Novel Nomogram Based on Quantitative MRI and Clinical Features for the Prediction of Neonatal Intracranial Hypertension

Intracranial hypertension (ICH) is a serious threat to the health of neonates. However, early and accurate diagnosis of neonatal intracranial hypertension remains a major challenge in clinical practice. In this study, a predictive model based on quantitative magnetic resonance imaging (MRI) data and clinical parameters was developed to identify neonates with a high risk of ICH. Newborns who were suspected of having intracranial lesions were included in our study. We utilized quantitative MRI to obtain the volumetric data of gray matter, white matter, and cerebrospinal fluid. After the MRI examination, a lumbar puncture was performed. The nomogram was constructed by incorporating the volumetric data and clinical features by multivariable logistic regression. The performance of the nomogram was evaluated by discrimination, calibration curve, and decision curve. Clinical parameters and volumetric quantitative MRI data, including postmenstrual age (p = 0.06), weight (p = 0.02), mode of delivery (p = 0.01), and gray matter volume (p = 0.003), were included in and significantly associated with neonatal intracranial hypertension risk. The nomogram showed satisfactory discrimination, with an area under the curve of 0.761. Our results demonstrated that decision curve analysis had promising clinical utility of the nomogram. The nomogram, incorporating clinical and quantitative MRI features, provided an individualized prediction of neonatal intracranial hypertension risk and facilitated decision making guidance for the early diagnosis and treatment for neonatal ICH. External validation from studies using a larger sample size before implementation in the clinical decision-making process is needed.

Two-Pore-Domain Potassium Channel TREK-1 Mediates Pulmonary Fibrosis through Macrophage M2 Polarization and by Direct Promotion of Fibroblast Differentiation

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by myofibroblast proliferation and abnormal accumulation of extracellular matrix in the lungs. After lung injury, M2 macrophages mediate the pathogenesis of pulmonary fibrosis by secreting fibrotic cytokines that promote myofibroblast activation. The TWIK-related potassium channel (TREK-1, also known as KCNK2) is a K2P channel that is highly expressed in cardiac, lung, and other tissues; it worsens various tumors, such as ovarian cancer and prostate cancer, and mediates cardiac fibrosis. However, the role of TREK-1 in lung fibrosis remains unclear. This study aimed to examine the effects of TREK-1 on bleomycin (BLM)-induced lung fibrosis. The results show that TREK-1 knockdown, mediated by the adenovirus or pharmacological inhibition of TREK-1 with fluoxetine, resulted in diminished BLM-induced lung fibrosis. TREK-1 overexpression in macrophages remarkably increased the M2 phenotype, resulting in fibroblast activation. Furthermore, TREK-1 knockdown and fluoxetine administration directly reduced the differentiation of fibroblasts to myofibroblasts by inhibiting the focal adhesion kinase (FAK)/p38 mitogen-activated protein kinases (p38)/Yes-associated protein (YAP) signaling pathway. In conclusion, TREK-1 plays a central role in the pathogenesis of BLM-induced lung fibrosis, which serves as a theoretical basis for the inhibition of TREK-1 as a potential therapy protocol for lung fibrosis.

Restrictive Use of Empirical Antibiotics Is Associated with Improved Short Term Outcomes in Very Low Birth Weight Infants: A Single Center, Retrospective Cohort Study from China

Antibiotics are essential for treating neonatal sepsis, but abuse or inappropriate use of antibiotics have harmful adverse effects. The inappropriate use of antibiotics has led to the significant increase in bacterial antimicrobial resistance in the neonatal intensive care unit (NICU). The aim of this study was to retrospectively analyze the changes in antibiotic usages in a NICU after the implementation of an antibiotic stewardship program and to determine the impact of this implementation on the short-term clinical outcomes of very low birth weight (VLBW) infants. The antibiotic stewardship program was initiated in the NICU in early 2015. For analysis, all eligible VLBW infants born from 1 January 2014 to 31 December 2016 were enrolled, and we classified the year 2014 as pre-stewardship, 2015 as during stewardship, and 2016 as post-stewardship. A total of 249 VLBW infants, including 96 cases in the 2014 group, 77 cases in the 2015 group, and 76 cases in the 2016 group, were included for final analysis. Empirical antibiotics were used in over 90% of VLBW infants in all three groups during their NICU stay. Over the 3-year period, the duration of an initial antibiotic course was significantly reduced. The proportion of patients receiving an initial antibiotic course for ≤3 days gradually increased (2.1% vs. 9.1% vs. 38.2%, p < 0.001), while the proportion of babies treated with an initial antibiotic course >7 days significantly decreased (95.8% vs. 79.2% vs. 39.5%, p < 0.001). The total days of antibiotic usage during the entire NICU stay also showed a significant reduction (27.0 vs. 21.0 vs. 10.0, p < 0.001). After adjusting for confounders, the reduction in antibiotic usage was associated with decreased odds of having an adverse composite short-term outcome (aOR = 5.148, 95% CI: 1.598 to 16.583, p = 0.006). To assess the continuity of antibiotic stewardship in the NICU, data from 2021 were also analyzed and compared to 2016. The median duration of an initial antibiotic course further decreased from 5.0 days in 2016 to 4.0 days in 2021 (p < 0.001). The proportion of an initial antibiotic course in which antibiotics were used for ≤3 days increased (38.2% vs. 56.7%, p = 0.022). Total antibiotic usage days during the entire NICU stay also decreased from 10.0 days in 2016 to 7.0 days in 2021 (p = 0.010). The finding of this study strongly suggests that restricting antibiotic use in VLBW infants is beneficial and can be achieved safely and effectively in China.

Therapeutic Effects of Omentin-1 on Pulmonary Fibrosis by Attenuating Fibroblast Activation via AMP-Activated Protein Kinase Pathway

Idiopathic pulmonary fibrosis (IPF) is a fatal age-related chronic lung disease, characterized by progressive scarring of the lungs by activated fibroblasts. The effect of omentin-1 against pulmonary fibrosis and fibroblast activation has not been investigated. The purpose of this experiment is to investigate the role of omentin-1 in bleomycin (BLM)-induced lung fibrosis and its mechanism. Our results showed that the loss of omentin-1 exaggerated lung fibrosis induced by BLM. On the contrary, adenoviral-overexpression of omentin-1 significantly alleviated BLM-induced lung fibrosis both in preventive and therapeutic regimens. Moreover, omentin-1 prevented fibroblast activation determined by a decreased number of S100A4+ (fibroblasts marker) α-SMA+ cells in vivo, and a decreased level of α-SMA expression both in mice primary fibroblasts and human primary fibroblasts induced by TGF-β in vitro. Furthermore, the phosphorylation of AMP-activated protein kinase (p-AMPK) was significantly lower in the fibrotic foci induced by BLM, and the adenoviral-overexpression of omentin-1 significantly increased the p-AMPK level in vivo. Importantly, Compound C, the inhibitor of AMPK, significantly attenuated the protective effect of omentin-1 on BLM-induced lung fibrosis and reversed the effect of omentin-1 on fibroblast activation by TGF-β. Omentin-1 can be a promising therapeutic agent for the prevention and treatment of lung fibrosis.

N-methyl-D-aspartate receptor blockers attenuate bleomycin-induced pulmonary fibrosis by inhibiting endogenous mesenchymal stem cells senescence

Background

Methods

Results

Conclusions

[Gender differences of genetic etiology in the incidence of major depressive disorder among Han freshmen]

Objective: To analyze the gender differences of genetic etiology in the incidence of major depression disorder among Han freshmen. Methods: A 1-year follow-up survey was carried out among 8 079 Han freshmen from Jining, Rizhao and Weifang without lifetime major depressive disorder (MDD) at baseline (April to October 2018) and 4 828 venous blood samples were also collected. After extracting DNA, Sequenom Mass Array time-of-flight mass spectrometry biochip technology was used to detect the genotypes of 17 single nucleotide polymorphisms (SNPs) MDD-related loci. Logistic regression was used for univariate analysis. Generalized multifactor dimension reduction was used to analyze gene-gene interactions. Composite International Diagnostic Interview (CIDI) 3.0 was used for MDD diagnosis. Results: The 1-year incidence of MDD among Han freshmen was 2.23% (95%CI: 1.91%-2.60%) and the gender difference of incidence between males (1.97%, 95%CI: 1.52%-2.56%) and females (2.39%, 95%CI: 1.98%-2.90%) was not statistically significant (P>0.05). AG genotype of rs768705 (nearby gene: TMEM161B) was a risk factor for MDD (OR=1.98, 95%CI: 1.24-2.83). The TC genotype of rs17727765 (nearby gene: CRYBA1) was only a risk factor for MDD in males (OR=9.61, 95%CI: 2.04-45.30). An 8-loci interaction model (PMFBP1, OLFM4, LHPP, ENOX1, TMEM161B, SPPL3, FBXL4 and L3MBTL2) could predict MDD in women with an accuracy rate of 60.05%. No effective prediction model was found for MDD in men. Conclusions: There might be gender differences in the genetic etiology of MDD. Further researches on the genetic causes of MDD in men should be explored.

Increased odds ratio for erectile dysfunction in COVID-19 patients

PURPOSE

Erectile dysfunction and COVID-19 share similar risk factors, including vascular disruption of integrity, cytokine release, cardiovascular disease, diabetes and obesity. The aim of this study was to investigate the association between erectile dysfunction and COVID-19 patients.

METHODS

Odds ratio for erectile dysfunction in patients with a history of COVID-19 with and without comorbidities were calculated using a patients' registry platform i2b2. ICD-10 diagnoses codes were accessed for queries and data were analyzed using logistic regression.

RESULTS

Patients with COVID-19 were 3.3 times more likely to have erectile dysfunction with 95% CI (2.8, 3.8). The association became stronger with odds ratio 4.8 (95% CI (4.1, 5.7)) after adjusting for age groups. The odds ratio remained the same after adjusting for smoking status with 3.5 (95% CI (3.0, 4.1)). After adjusting for race, COVID-19 patients were 2.6 (95% CI (2.2, 3.1)) times more likely to have erectile dysfunction. The odds ratio were 1.6, 1.8, 1.9 and 2.3 after adjusting for respiratory disease, obesity, circulatory disease and diabetes, respectively.

CONCLUSION

COVID-19 and erectile dysfunction are strongly associated even after adjustment for known risk factors and demographics.

Effects of Excessive Activation of N-methyl-D-aspartic Acid Receptors in Neonatal Cardiac Mitochondrial Dysfunction Induced by Intrauterine Hypoxia

Intrauterine hypoxia is a common complication during pregnancy and could increase the risk of cardiovascular disease in offspring. However, the underlying mechanism is controversial. Memantine, an NMDA receptor antagonist, is reported to be a potential cardio-protective agent. We hypothesized that antenatal memantine treatment could prevent heart injury in neonatal offspring exposed to intrauterine hypoxia. Pregnant rats were exposed to gestational hypoxia or antenatal memantine treatment during late pregnancy. Newborns were then sacrificed to assess multiple parameters. The results revealed that Intrauterine hypoxia resulted in declining birth weight, heart weight, and an abnormally high heart weight/birth weight ratio. Furthermore, intrauterine hypoxia caused mitochondrial structural, functional abnormalities and decreased expression of DRP1, and upregulation of NMDAR1 in vivo. Antenatal memantine treatment,an NMDARs antagonist, improved these changes. In vitro, hypoxia increased the glutamate concentration and expression of NMDAR1. NMDAR activation may lead to similar changes in mitochondrial function, structure, and downregulation of DRP1 in vitro. Pharmacological blockade of NMDARs by the non-competitive NMDA antagonist MK-801 or knockdown of the glutamate receptor NR1 significantly attenuated the increased mitochondrial reactive oxygen species and calcium overload-induced by hypoxia exposure. These facts suggest that memantine could provide a novel and promising treatment for clinical use in intrauterine hypoxia during pregnancy to protect the cardiac mitochondrial function in the offspring. To our best knowledge, our research is the first study that shows intrauterine hypoxia can excessively activate cardiac NMDARs and thus cause mitochondrial dysfunction.

Simulation-based design study for the passive shielding of the COSINUS dark matter experiment

The COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) experiment aims at the detection of dark matter-induced recoils in sodium iodide (NaI) crystals operated as scintillating cryogenic calorimeters. The detection of both scintillation light and phonons allows performing an event-by-event signal to background discrimination, thus enhancing the sensitivity of the experiment. The choice of using NaI crystals is motivated by the goal of probing the long-standing DAMA/LIBRA results using the same target material. The construction of the experimental facility is foreseen to start by 2021 at the INFN Gran Sasso National Laboratory (LNGS) in Italy. It consists of a cryostat housing the target crystals shielded from the external radioactivity by a water tank acting, at the same time, as an active veto against cosmic ray-induced events. Taking into account both environmental radioactivity and intrinsic contamination of materials used for cryostat, shielding and infrastructure, we performed a careful background budget estimation. The goal is to evaluate the number of events that could mimic or interfere with signal detection while optimising the geometry of the experimental setup. In this paper we present the results of the detailed Monte Carlo simulations we performed, together with the final design of the setup that minimises the residual amount of background particles reaching the detector volume.

A Cross-Sectional Nationwide Study on Accessibility and Availability of Neonatal care Resources in Hospitals of China: Current Situation, Mortality and Regional Differences: Neonatal Care Resources and Newborn Mortality in China

Background

To investigate the current situation of neonatal care resources (NCR), newborn mortality rates (NMR), regional differences and existing challenges in China.

Methods

By using a self-designed questionnaire form and the cross-sectional method, we conducted a survey of all hospitals equipped with neonatal facilities in China from March 2019 to March 2020 with respect to the level and nature of these hospitals, the number of newborn beds and NICU beds, the number of neonatal pediatricians, and the development of therapeutic techniques. The data about the newborn births and deaths were retrieved from the annual statistics of the health commissions of the related provinces, autonomous regions and municipalities.

Finding

Included in this nationwide survey were 3,020 hospitals from all 22 provinces, 5 autonomous regions and 4 municipalities directly under the Central Government of Mainland China, with a 100% response rate. They included 1,183 (39.2%) level-3 (L3) hospitals, 1629 (53.9%) L-2 hospitals and 208 (6.9%) L-1 hospitals. Geographically, 848 (31.4%) hospitals were distributed in Central China, 983 (32.5%) hospitals in East China, and 1,089 (36.1%) in West China. The 3,020 included hospitals were altogether equipped with 75,679 newborn beds, with a median of 20 (2-350) beds, of which 2,286 hospitals (75.7%) were equipped with neonatal intensive care units (NICU), totaling 28,076 NICU beds with a median of 5 (1-160) beds. There were altogether 27,698 neonatal pediatricians in these hospitals, with an overall doctor-bed ratio of 0.366. There were 48.18 newborn beds and 17.87 NICU beds per 10,000 new births in China. In East, Central and West China, the number of neonatal beds, NICU beds, neonatal pediatricians, and attending pediatricians or pediatricians with higher professional titles per 10,000 newborns was 42.57, 48.64 and 55.67; 17.07, 18.66 and 18.17; 16.26, 16.51 and 20.81; and 10.69, 10.81 and 11.29, respectively. However, when the population and area are taken into consideration and according to the health resources density index (HRDI), the number of newborn beds, NICU beds and neonatal pediatricians in West China was significantly lower than that in Central and East China. In addition, only 10.64% of the neonatal pediatricians in West China possessed the Master or higher degrees, vs. 31.7% in East China and 20.14% in Central China. On the contrary, the number of neonatal pediatricians with a lower than Bachelor degree in West China was significantly higher than that in Central and East China (13.28% vs. 7.36% and 4.28%). Technically, the application rate of continuous positive airway pressure (CPAP) and conventional mechanical ventilation (CMV) in L-1 hospitals of West China was lower than that in Central and East China. According to the statistics in 2018, the newborn mortality rate (NMR) in West China was significantly higher than that in Central and East China.

Interpretation

China has already possessed relatively good resources for neonatal care and treatment, which is the primary reason for the rapid decrease in the NMR in China. However, there are still substantial regional differences. The density of health resources, the level of technical development and educational background of neonatal pediatricians in West China still lag behind those in other regions of China and need to be further improved and upgraded.

Funding

This research work was funded by National Natural Science Foundation of China (81671504) and United Nations International Children's Emergency Fund (CHINA-UNICEF501MCH).

Mortality and Morbidity of Infants Born Extremely Preterm at Tertiary Medical Centers in China From 2010 to 2019

IMPORTANCE

Extreme prematurity is associated with a substantial burden on health care systems worldwide. However, little is known about the prognosis of infants born extremely preterm in developing countries, such as China.

OBJECTIVE

To describe survival and major morbidity among infants born extremely preterm in China over the past decade.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted from January 1, 2010, through December 31, 2019. Included individuals were infants with gestational age less than 28 weeks discharged from 1 of 68 neonatal intensive care units located in 31 provinces in China. Data were analyzed from August through October 2020.

EXPOSURE

Extremely preterm birth.

MAIN OUTCOMES AND MEASURES

Survival to discharge and major morbidity (ie, bronchopulmonary dysplasia, grades III-IV intraventricular hemorrhage, white matter injury, stage II-III necrotizing enterocolitis, sepsis, or severe retinopathy of prematurity) were measured.

RESULTS

Among 8514 eligible infants, 5295 (62.2%) were male and 116 infants (2.0%) were small for gestational age (SGA). Overall, 5302 infants (62.3%) survived to discharge. The survival rate was 1 of 21 infants (4.8%) at 22 weeks, 13 of 71 infants (18.3%) at 23 weeks, 144 of 408 infants (35.3%) at 24 weeks, 480 of 987 infants (48.6%) at 25 weeks, 1423 of 2331 infants (61.0%) at 26 weeks, and 3241 of 4692 infants (69.1%) at 27 weeks. Survival increased from 136 of 241 infants (56.4%; 95% CI, 50.1%-62.7%) in 2010 to 1110 of 1633 infants (68.0%; 95% CI, 65.7%-70.2%) in 2019 for infants born at 24 to 27 weeks (mean difference, 11.5%; 95% CI, 4.9%-18.2%; P < .001), without a significant change for infants born at less than 24 weeks. Major morbidity was found in 5999 of 8281 infants overall, for a rate of 72.4%, which increased from 116 of 223 infants (52.0%; 95% CI, 45.4%-58.6%) to 1363 of 1656 infants (82.3%; 95% CI, 80.5%-84.1%) from 2010 to 2019 (mean difference, 30.3%; 95% CI, 23.5%-37.1%, P < .001). Regional variations in survival were identified, with an almost 2-fold increase (1.94-fold; 95% CI, 1.66-2.27; P < .001) from 188 of 474 infants (39.7%) in northwest China to 887 of 1153 infants (76.9%) in north China. Gestational age (adjusted risk ratio [aRR], 1.084; 95% CI, 1.063-1.105; P < .001), birth weight (aRR, 1.028; 95% CI, 1.020-1.036; P < .001), premature rupture of membranes (aRR, 1.025; 95% CI, 1.002-1.048; P = .03), and antenatal steroids (aRR, 1.029; 95% CI, 1.004-1.055; P = .02) were associated with improved survival, while being born SGA (aRR, 0.801; 95% CI, 0.679-0.945; P = .01), being male (aRR, 0.975; 95% CI, 0.954-0.997; P = .02), multiple birth (aRR, 0.955; 95% CI, 0.929-0.982; P = .001), having a mother with gestational diabetes (aRR, 0.946; 95% CI, 0.913-0.981; P = .002), and low Apgar score (aRR, 0.951; 95% CI, 0.925-0.977; P < .001) were found to be risk factors associated with decreased chances of survival.

CONCLUSIONS AND RELEVANCE

This study found that infants born extremely preterm were at increased risk of mortality and morbidity in China, with a survival rate that improved over time and a major morbidity rate that increased. These findings suggest that more active and effective treatment strategies are needed, especially for infants born at gestational age 25 to 27 weeks.

The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

MiR-125b Improves acute myocardial infarction in rats by regulating P38/Sirtl/P53 signaling pathway

The aim of this study was to investigate the differential expression of micro ribonucleic acid (miR)- 125b in acute myocardial infarction (AMI) cases, and to explore the mechanism by which it affects cardiac function. Sprague-Dawley rats were used for AMI modeling, and the expression of miR-125b in the myocardial tissues of AMI rats was detected via fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Thereafter, the target genes of miR-125b were collected and uploaded to WenGestalt for gene ontology (GO) and pathway enrichment analyses. In-vitro experiments were then applied to determine the p38-sirtuin 1 (Sirt1)-p53 expression change and cardiomyocyte apoptosis under down-regulation of miR-125b. Next, the interaction between miR-125b and its target genes was verified by luciferase reporter gene assay. The expression of miR-125b in the cardiac tissues was decreased in theAMI group compared with that in the Sham group (p<0.05). The luciferase reporter gene assay confirmed that p38 was the target gene of miR-125b. Furthermore, the down-regulated expression of miR-125b in H9C2 cells up-regulated the protein expressions of p38 and phosphorylated p38, thus activating the Sirt1-p53 signaling pathway. Moreover, the down-regulation of miR-125b expression in H9C2 cells gave rise to the elevated apoptosis rate, and the down-regulated expression of miR-125b induced cardiomyocyte apoptosis through activating the p38-Sirt1-p53 signaling pathway.

Analyzing the Effects of Intrauterine Hypoxia on Gene Expression in Oocytes of Rat Offspring by Single Cell Transcriptome Sequencing

Intrauterine hypoxia is one of the most frequently occurring complications during pregnancy, and the effects of antenatal hypoxia in offspring are not restricted to the perinatal period. Previous studies have reported on this phenomenon, which is usually described as multigenerational or transgenerational inheritance. However, the exact mechanism of this type of inheritance is still not clear. Therefore, in the present study, we investigated the alteration in the gene expression of oocytes, derived from intrauterine hypoxia rats and their offspring, by transcriptome sequencing. Our results showed that 11 differentially expressed genes were inherited from the F1 to F2 generation. Interestingly, these differentially expressed genes were enriched in processes predominantly involved in lipid and insulin metabolism. Overall, our data indicated that alteration in the gene expression of oocytes may be associated with some metabolic diseases and could potentially be the basis of transgenerational or multigenerational inheritance, induced by an adverse perinatal environment.

Bone mineral density gains with a second 12-month course of romosozumab therapy following placebo or denosumab

Romosozumab is a therapy that stimulates bone formation and reduces bone resorption. In this study of postmenopausal women with low BMD, a second course of romosozumab following a period off treatment or on denosumab increased or maintained BMD, respectively, and was well tolerated, providing insight into treatment sequence options.

INTRODUCTION

In patients with high fracture risk, therapies that stimulate bone formation provide rapid BMD gains; currently available agents, parathyroid hormone receptor agonists, are limited to a 2-year lifetime exposure and generally used for a single treatment course. However, for long-term osteoporosis management, a second treatment course may be appropriate. Romosozumab, a therapy with the dual effect of increasing bone formation and decreasing bone resorption, reduces fracture risk within 12 months. Here, we report efficacy and safety of a second romosozumab course.

METHODS

In this phase 2, dose-finding study, postmenopausal women with low bone mass (T-score ≤ - 2.0 and ≥ - 3.5) received romosozumab or placebo (month 0-24) followed by placebo or denosumab (month 24-36); participants then received a year of romosozumab (month 36-48).

RESULTS

Of 167 participants who entered the month 36-48 period, 35 had been initially randomized to romosozumab 210 mg monthly. In participants who received romosozumab 210 mg monthly followed by placebo, a second romosozumab course (n = 19) increased BMD by amounts similar to their initial treatment (month 0-12) at the lumbar spine (12.4%; 12.0%, respectively) and total hip (6.0%; 5.5%, respectively). Following denosumab, a second romosozumab course (n = 16) increased BMD at the lumbar spine (2.3%) and maintained BMD at the total hip. Safety profiles were similar between first and second romosozumab courses.

CONCLUSIONS

After 12 months off-treatment, a second romosozumab course again led to rapid and large BMD gains. Following denosumab, BMD gains with romosozumab were smaller than with initial treatment. No new safety findings were observed during the second course.

NMDA receptor activation inhibits the protective effect of BM‑MSCs on bleomycin‑induced lung epithelial cell damage by inhibiting ERK signaling and the paracrine factor HGF

Endoplasmic reticulum (ER) stress in alveolar epithelial cells (AECs) is associated with the pathogenesis of pulmonary fibrosis. Bone marrow‑derived mesenchymal stromal cells (BM‑MSCs) can exert protective effects on ER‑stressed AECs via paracrine signaling. In the present study, mouse lung epithelial (MLE)‑12 cells were directly stimulated with various concentrations of bleomycin (BLM). MLE‑12 cell apoptosis was detected by flow cytometry, and Ki67 expression was detected by immunofluorescence to reflect cell proliferation. The results revealed that BLM increased the protein expression levels of X‑box binding protein 1 and immunoglobulin heavy chain‑binding protein, thus inducing ER stress, and caused cell dysfunction by inhibiting proliferation and promoting apoptosis. In addition, MSC‑derived conditioned medium (MSC‑CM) protected MLE‑12 cells from BLM‑induced injury, by reducing ER stress, promoting cell proliferation and inhibiting cell apoptosis. Our previous studies reported that N‑methyl‑D‑aspartate (NMDA) receptor activation partially inhibits the antifibrotic effect of BM‑MSCs on BLM‑induced pulmonary fibrosis through downregulating the paracrine factor hepatocyte growth factor (HGF). In the present study, the synthesis and secretion of HGF were detected by western blotting and ELISA, respectively. Results further demonstrated that NMDA inhibited the synthesis and secretion of HGF in BM‑MSCs, and NMDA‑preconditioned MSC‑CM had no protective effects on BLM‑induced injury in MLE‑12 cells. In addition, activation of the NMDA receptor decreased the phosphorylation levels of extracellular signal‑regulated kinase (ERK)1/2 in BM‑MSCs. Using Honokiol and FR180204, the activator and inhibitor of ERK1/2, respectively, it was then revealed that Honokiol partially eliminated the decrease in HGF expression, whereas FR180204 further promoted the reduction in HGF caused by NMDA. Collectively, these findings suggested that NMDA receptor activation may downregulate HGF by inhibiting ERK signaling in BM‑MSCs, thus weakening their protective effects on BLM‑induced lung epithelial cell damage.

Excessive activation of NMDA receptor inhibits the protective effect of endogenous bone marrow mesenchymal stem cells on promoting alveolarization in bronchopulmonary dysplasia

We studied the role of bone marrow mesenchymal stem cells (MSCs) in our established model of bronchopulmonary dysplasia (BPD) induced by intrauterine hypoxia in the rat. First, we found that intrauterine hypoxia can reduce the number of MSCs in lungs and bone marrow of rat neonates, whereas the administration of granulocyte colony-stimulating factor or busulfan to either motivate or inhibit bone marrow MSCs to lungs altered lung development. Next, in vivo experiments, we confirmed that intrauterine hypoxia also impaired bone marrow MSC proliferation and decreased cell cycling activity. In vitro, by using the cultured bone marrow MSCs, the proliferation and the cell cycling activity of MSCs were also reduced when N-methyl-d-aspartic acid (NMDA) was used as an NMDA receptor (NMDAR) agonist. When MK-801 or memantine as NMDAR antagonists in vitro or in vivo was used, the reduction of cell cycling activity and proliferation were partially reversed. Furthermore, we found that intrauterine hypoxia could enhance the concentration of glutamate, an amino acid that can activate NMDAR, in the bone marrow of neonates. Finally, we confirmed that the increased concentration of TNF-ɑ in the bone marrow of neonatal rats after intrauterine hypoxia induced the release of glutamate and reduced the cell cycling activity of MSCs, and the latter could be partially reversed by MK-801. In summary, intrauterine hypoxia could decrease the number of bone marrow MSCs that could affect lung development and lung function through excessive activation of NMDAR that is partially caused by TNF-ɑ.

[Effect of biofeedback therapy on metabolic syndrome under different levels of job stress]

Objective: To investigate the effect of biofeedback therapy on metabolic syndrome (MS) and the effect of different levels of job stress on the outcome. Methods: The physicians in tertiary hospitals who were diagnosed with MS from January to December, 2016 were divided into biofeedback group and health education group according to different intervention methods, and moderate group, medium group, and high group according to different levels of job stress. A 6-month intervention was implemented from May to October, 2017. A two-way factorial design was used to analyze the main effect of biofeedback on physical and biochemical parameters and the interaction of biofeedback and job stress. Results: After 6 months of intervention, the patients in both the biofeedback group and the moderate group had significantly decreased waist circumference, body mass index, systolic blood pressure (SBP) , diastolic blood pressure (DBP) , and levels of triglyceride (TG) , total cholesterol, low-density lipoprotein cholesterol (LDL-C) , and fasting plasma glucose (FPG) and a significantly increased level of high-density lipoprotein cholesterol (HDL-C) (all P<0.05) ; the patients in both the health education group and the moderate group had significantly decreased SBP, DBP, and levels of TG, LDL-C, and FPG (P<0.05) . The factorial analysis of variance showed that there was a synergistic interaction between the intervention method and job stress level in SBP, DBP, TG, HDL-C, LDL-C, and FPG among MS patients (P<0.05) . The high group had significantly more improvements in all indices compared with the medium group and the moderate group (P<0.05) . Conclusion: Biofeedback therapy can effectively improve blood pressure, blood lipids, and blood glucose in MS patients, and is more effective for patients with high job stress level.

Memantine ameliorates pulmonary inflammation in a mice model of COPD induced by cigarette smoke combined with LPS

An enhanced chronic inflammatory response in the airways has been regarded as a critical characteristic of chronic obstructive pulmonary disease (COPD). Memantine, an N-methyl-d-aspartate (NMDA) receptors antagonist, has been reported to alleviate lung inflammation. In this study, we investigated the effect and mechanism of memantine on the COPD model induced by cigarette smoke (CS) combined with LPS. Mice and RAW264.7 cells were treated with LPS in the presence or absence of CS. We performed H&E staining to analysis the lung histopathological characteristics. Cytokines (IL-6, TNF-α, and IFN-γ) levels in bronchoalveolar lavage fluid (BALF), lung tissue homogenates and RAW264.7 cell culture medium were determined. Glutamate levels in plasma and culture medium of RAW264.7 were determined. The intracellular Ca2+ flux in RAW264.7 cells was measured by fluo-3 AM staining. The protein levels of NR-1, xCT, ERK1/2, and AKT signaling in the lung tissue and cells were investigated. The result showed that CS and LPS stimulation caused inflammation response, a significant increase in the release of cytokines, including TNF-α, IL-6, and IFN-γ, the elevated release of glutamate and protein levels of NR-1 and xCT, increased Ca2+ influx, and the activation of the ERK1/2 pathway in vitro and in vivo. The above effects of CS and LPS stimulation could be significantly attenuated by memantine treatment. In conclusion, memantine can effectively ameliorate pulmonary inflammation in CS + LPS-induced COPD in mice via reducing NR-1 and xCT expression, glutamate release, Ca2+ influx, and the phosphorylation of Erk1/2. We provided a possible mechanism by which memantine ameliorates COPD in mice.

Thermal Camera Based Physiological Monitoring with an Assistive Robot

This paper presents a physiological monitoring system for assistive robots using a thermal camera. It is based on the detection of subtle changes in temperature observed on different parts of the face. First, we segment and estimate these face regions on thermal images. Then, by applying Fourier analysis on temperature data, we estimate respiration and heartbeat rate. This physiological monitoring system has been integrated in an assistive robot for elderly people at home, as part of the ENRICHME project. Its performance has been evaluated on a new thermal dataset for physiological monitoring, which is made publicly available for researchpurposes.

NMDA receptor activation inhibits the antifibrotic effect of BM-MSCs on bleomycin-induced pulmonary fibrosis

Endogenous glutamate (Glu) release and N-methyl-d-aspartate (NMDA) receptor (NMDAR) activation are associated with lung injury in different animal models. However, the underlying mechanism is unclear. Bone marrow-derived mesenchymal stem cells (BM-MSCs), which show potential use for immunomodulation and tissue protection, play a protective role in pulmonary fibrosis (PF) process. Here, we found the increased Glu release from the BM cells of bleomycin (BLM)-induced PF mice in vivo. BLM stimulation also increased the extracellular Glu in BM-MSCs via the antiporter system x_c⁻ in vitro. The gene expression of each subunit of NMDAR was detected in BM-MSCs. NMDAR activation inhibited the proliferation, migration, and paracrine function of BM-MSCs in vitro. BM-MSCs were derived from male C57BL/6 mice, transfected with lentiviral vectors carrying the enhanced green fluorescence protein gene, pretreated with NMDA, and transplanted into the female recipient mice that were intratracheally injected with BLM to induce PF. Transplantation of NMDA-pretreated BM-MSCs significantly aggravated PF as compared with that in the normal BM-MSCs transplantation group. The sex determination gene Y chromosome and green fluorescence protein genes of BM-MSCs were detected to observe BM-MSCs homing in the fibrotic lungs. Moreover, NMDAR activation inhibited BM-MSC migration by downregulating the stromal cell-derived factor-1/C-X-C chemokine receptor type 4 signaling axis. NMDAR activation aggravated the transforming growth factor-β1-induced extracellular matrix production in alveolar epithelial cells and fibroblasts through the paracrine effects of BM-MSCs. In summary, these findings suggested that NMDAR activation-mediated Glu excitotoxicity induced by BLM in BM-MSCs abolished the therapeutic effects of normal BM-MSCs transplantation on BLM-induced PF.

Persistence at 24 months with denosumab among postmenopausal women with osteoporosis: results of a prospective cohort study

Persistence with prescribed medications for chronic diseases is important; however, persistence with osteoporosis treatments is historically poor. In this prospective cohort study of postmenopausal women treated for osteoporosis in real-world clinical practice settings in the USA and Canada, 24-month persistence with denosumab was 58%.

PURPOSE

Patients who persist with their prescribed osteoporosis treatment have increased bone mineral density (BMD) and reduced risk of fracture. Twelve-month persistence with denosumab in routine clinical practice is as high as 95%, but there are limited data on longer-term persistence with denosumab in this setting.

METHODS

This single-arm, prospective, cohort study evaluated 24-month persistence with denosumab administered every 6 months in postmenopausal women receiving treatment for osteoporosis in real-world clinical practice in the USA and Canada. Endpoints and analyses included the percentage of patients who persist with denosumab at 24 months (greater than or equal to four injections with a gap between injections of no more than 6 months plus 8 weeks), the total number of injections received by each patient, changes in BMD in persistent patients, and the incidence of serious adverse events (SAEs) and fractures.

RESULTS

Among 935 enrolled patients, 24-month persistence was 58% (50% in US patients and 75% in Canadian patients). A majority of patients received at least four injections over the observation period (62% of US patients and 81% of Canadian patients). Among patients who were persistent at 24 months and who had a baseline, 12-month, and 24-month DXA scan, mean BMD increased from baseline to 24 months by 7.8% at the lumbar spine and 2.1% at the femoral neck. SAEs and fractures were reported for 122 (13.0%) patients and 54 (5.8%) patients, respectively.

CONCLUSIONS

Persistence with denosumab for 24 months yields improvement in BMD among postmenopausal women with osteoporosis treated in routine clinical practice in the USA and Canada.

Alloy and composition dependence of hydrogen embrittlement susceptibility in high-strength steel fasteners

High-strength steel fasteners characterized by tensile strengths above 1100 MPa are often used in critical applications where a failure can have catastrophic consequences. Preventing hydrogen embrittlement (HE) failure is a fundamental concern implicating the entire fastener supply chain. Research is typically conducted under idealized conditions that cannot be translated into know-how prescribed in fastener industry standards and practices. Additionally, inconsistencies and even contradictions in fastener industry standards have led to much confusion and many preventable or misdiagnosed fastener failures. HE susceptibility is a function of the material condition, which is comprehensively described by the metallurgical and mechanical properties. Material strength has a first-order effect on HE susceptibility, which increases significantly above 1200 MPa and is characterized by a ductile--brittle transition. For a given concentration of hydrogen and at equal strength, the critical strength above which the ductile-brittle transition begins can vary due to second-order effects of chemistry, tempering temperature and sub-microstructure. Additionally, non-homogeneity of the metallurgical structure resulting from poorly controlled heat treatment, impurities and non-metallic inclusions can increase HE susceptibility of steel in ways that are measurable but unpredictable. Below 1200 MPa, non-conforming quality is often the root cause of real-life failures.This article is part of the themed issue 'The challenges of hydrogen and metals'.

Mesenchymal stem cells in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a major cause of respiratory failure in critically ill patients and common outcome of various lung interstitial diseases. Its mortality remains high, and no effective pharmacotherapy, in addition to artificial ventilation and transplantation, exists. As such, the administration of mesenchymal stem or stromal cells (MSCs) is currently investigated as a new therapeutic method for pulmonary fibrosis. Clinical trials on MSC-based therapy as a potential treatment for lung injury and fibrosis are also performed. MSCs can migrate to injured sites and secrete multiple paracrine factors and then regulate endothelial and epithelial permeability, decrease inflammation, enhance tissue repair, and inhibit bacterial growth. In this review, recent studies on stem cells, particularly MSCs, involved in alleviating lung inflammation and fibrosis and their potential MSC-induced mechanisms, including migration and differentiation, soluble factor and extracellular vesicle secretion, and endogenous regulatory functions, were summarized.

Combined Kidney Transplantation and Splenic Fossa Auxiliary Heterotopic Liver Transplantation in a Highly Sensitized Recipient: A Case Report

BACKGROUND

Combined kidney and auxiliary orthotopic liver transplantation from the same donor is used to treat highly sensitized renal transplant recipients. Auxiliary liver can protect the transplanted kidney against hyperacute rejection.

METHODS

In the current case, combined kidney and splenic fossa auxiliary heterotopic liver transplantation was performed from the same donor for a highly sensitized recipient without preoperative preconditioning. No postoperative hyperacute rejection occurred.

RESULTS

Seven days after surgery, preexisting antibody levels rose and decreased after treatment; meanwhile, the function of transplanted kidney returned to normal. During 24 months of follow-up, the grafts showed good blood perfusion and functioned well. The levels of preexisting antibodies, donor-specific antibodies (DSA) and C1q-fixing human leukocyte antigen (C1q-HLA) antibodies, all decreased.

CONCLUSIONS

Combined kidney and splenic fossa auxiliary heterotopic liver transplantation can be used in renal transplantation for highly sensitized recipients.

Psychological distress and type 2 diabetes mellitus: a 4-year policemen cohort study in China

OBJECTIVES

This study investigated whether psychological distress predicts the development of type 2 diabetes mellitus (T2DM) and if the association differs between populations at a high or low diabetes risk level among Chinese police officers.

DESIGN

Prospective cohort study.

SETTING

Single centre.

PARTICIPANTS

6559 participants underwent clinical measurements at the hospital in April 2007. 5811 police officers participated in the follow-up consisting of new-onset diabetes (NOD) events occurring annually between 2008 and 2011.

PRIMARY OUTCOME MEASURES

Baseline data were collected from policemen who completed the Symptom Checklist 90-Revised (SCL-90-R) questionnaire and a self-designed questionnaire. Psychological distress was measured by the SCL-90-R questionnaire. Hong Kong Chinese Diabetes Risk Score (HKCDRS) was used to evaluate the risk of T2DM, and the participants were divided into low-risk group and high-risk group based on the HKCDRS. Cox proportional hazards regression was used to calculate the HRs of the incidence of T2DM related to psychological distress and further stratified the analysis based on HKCDRS.

RESULTS

Among 5811 participants, 179 subjects developed NOD during the 4-year follow-up. 54 subjects (1.63%) with a HKCDRS 0-7 vs 125 subjects (4.98%) with a HKCDRS>7 developed NOD (p<0.05). There was a significant association between psychological distress and T2DM (HR=1.46; 95% CI 1.05 to 2.02). Among the participants with a high-risk score (HKCDRS>7), 7.07% of those with psychological distress developed T2DM compared with 4.43% of participants without psychological distress (p<0.05). The corresponding adjusted HR for psychological distress was 1.61 (95% CI 1.10 to 2.37).

CONCLUSIONS

Psychological distress is an independent risk factor for T2DM in this prospective cohort study. Stratification analysis indicated that psychological distress was associated with T2DM in a high-risk level population.

Effect of crystallographic orientation on the tribological behavior of electrodeposited Zn coatings

Tribo/transfer film evolution during sliding wear of steel contact on oriented Zn coatings.

A study on the susceptibility of allogeneic human hepatocytes to porcine endogenous retrovirus

OBJECTIVE

Porcine endogenous retrovirus (PERV) is a virus that can be integrated into porcine genome. It has been proved that PERV can infect the cells of a variety of species. However, little is known about the infectivity of PERV to human hepatocytes. The present study focused on the susceptibility of primary human hepatocytes to PERV.

MATERIALS AND METHODS

Cell culture supernatant containing PERV was used to infect primary allogeneic hepatocytes and human embryonic kidney cell line HEK-293. The integration of PERV into the genome and PERV expression were detected by using PCR and RT-PCR.

RESULTS

Gene and mRNA sequences of PERV were detected in HEK-293 cells; however, viral gene expression was not detected in 3 groups of primary allogeneic hepatocytes.

CONCLUSIONS

HEK-293 cells can be infected by PERV, but 3 groups of primary allogeneic hepatocytes were not sensitive to PERV, indicating PERV had no infectivity to primary human hepatocytes.

A randomized study evaluating cinacalcet to treat hypercalcemia in renal transplant recipients with persistent hyperparathyroidism

Persistent hyperparathyroidism (HPT) after kidney transplantation (KTx) is associated with hypercalcemia, hypophosphatemia and abnormally high levels of parathyroid hormone (PTH). In this randomized trial, cinacalcet was compared to placebo for the treatment of hypercalcemia in adult patients with persistent HPT after KTx. Subjects were randomized 1:1 to cinacalcet or placebo with randomization stratified by baseline corrected total serum calcium levels (≤11.2 mg/dL [2.80 mmol/L] or >11.2 mg/dL [2.80 mmol/L]). The primary end point was achievement of a mean corrected total serum calcium value<10.2 mg/dL (2.55 mmol/L) during the efficacy period. The two key secondary end points were percent change in bone mineral density (BMD) at the femoral neck and absolute change in phosphorus; 78.9% cinacalcet- versus 3.5% placebo-treated subjects achieved the primary end point with a difference of 75.4% (95% confidence interval [CI]: 63.8, 87.1), p<0.001. There was no statistical difference in the percent change in BMD at the femoral neck between cinacalcet and placebo groups, p=0.266. The difference in the change in phosphorus between the two arms was 0.45 mg/dL (95% CI: 0.26, 0.64), p<0.001 (nominal). No new safety signals were detected. In conclusion, hypercalcemia and hypophosphatemia were effectively corrected after treatment with cinacalcet in patients with persistent HPT after KTx.

MicroRNA expression profile in intrauterine hypoxia-induced pulmonary hypoplasia in rats

Hypoxia is necessary for fetal development; however, excess hypoxia is detrimental. The mechanisms underlying the effects of hypoxia on lung development remain unclear, although important roles of microRNAs (miRNAs) during lung development have recently been established. However, the effect on lung development at an miRNA expression level, following changes in oxygen tension, have not yet been studied. In the present study, pregnant rats were exposed to a fraction of inspired oxygen of 10.5 or 21% for two days on gestation day 19, following which the body weight, lung wet weight, radial alveolar count (RAC) and mean linear intercept (Lm) of the newborn pups were analyzed on postnatal day 1. To define the role of miRNAs during lung development following intrauterine hypoxia exposure, the miRNA expression pattern was profiled using a miRNA microarray. The newborn rats in the hypoxic group exhibited statistically significant decreases in body weight, lung weight and the RAC, as well as a marked increase in the Lm. A total of 69 miRNAs were identified to have significant changes in expression, including 55 upregulated and 14 downregulated miRNAs. Quantitative polymerase chain reaction was used to validate the microarray results of six selected miRNAs. Therefore, the results indicated that late gestation intrauterine hypoxia exposure may cause lung injury and miRNAs may play important roles in this process.

[Protective effect of NMDA receptor antagonist memantine on acute lung injury in mice]

OBJECTIVE

To investigate the protective effect of a non-specific NMDA receptor antagonist memantine on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.

METHODS

Healthy male mice were divided into 4 groups: a normal group, a memantine group, an ALI group and a memantine+ALI group. The ALI group was induced by intraperitoneal injection of LPS (10 mg/kg). Memantine (10 mg/kg) was injected intraperitoneally before the injection of LPS to determine the effect of blockade of NMDA receptor in the memantine+ALI group. The lung wet/dry ratio was detected. HE staining was preformed to show the morphological changes in the lung tissue. Myeloperoxidase enzyme (MPO) activity and malondialdehyde (MDA) content in the lung tissue were detected. ELISA was used to detect the tumor necrosis factor-α (TNF-α) content and lactate dehydrogenase (LDH) activity in the bronchoalveolar lavage fluid (BALF).

RESULTS

Memantine pretreatment improved the LPS-induced ALI lung tissue morphological changes, reduced their lung wet/dry ratio, the levels of TNF-α and LDH activity in BALF, and also reduced the MPO and MDA content in the lung tissue.

CONCLUSION

Blockade of NMDA receptors can ameliorate LPS-induced mice ALI.

[Influence of intrauterine hypoxia on the lung blood vessel development in rats after birth and expression of VEGF in the lung]

OBJECTIVE

To observe the effect of intrauterine hypoxia on the development of rat lung after birth under ordinary pressure and normoxia, on the expression of vascular endothelial growth factor (VEGF) in the lung as the age increasing after birth, and to provide experimental basis for the treatment of intrauterine hypoxia after baby was born.

METHODS

Intrauterine hypoxia models were established. The rats were divided into an air-control group (the control group) and a hypoxic 6-day group (the hypoxic group). All rats were fed under normal pressure and normoxia after they were born. At postnatal 7, 14, and 21 days, we measured the pulmonary vascular morphometry, detected the expression of VEGF protein with immunohistochemisty, the expression of VEGF mRNA with real-time PCR, and observed the alteration of capillary endothelium in the lung tissues under the electron microscope.

RESULTS

The expression of VEGF protein and VEGF mRNA in the 2 groups increased as the rats grew, but the expression increased slower in the hypoxic group than that in the control group. The increase curve of the 2 groups crossed. There was no significant difference between the 2 groups in the pulmonary vascular morphometry at each experiment time point. Hyperplasia of capillary endothelium decreased with age. Cellular edema of capillary endothelium was obvious especially at the 14th day after birth under the electron microscope.

CONCLUSION

The expression of VEGF protein and VEGF mRNA has slower increase in the intrauterine hypoxic rats than that in the normal control rats. The expression of VEGF may influence the development of lung vessel after rats was born.